This invention relates to apparatus for switching direct current (DC) electric power. More particularly it relates to apparatus of the aforementioned type which is non-polarized or bidirectional, i.e. its performance is independent of polarity of the current at the power terminals, and can switch high voltage DC power. Still more particularly, the invention is related to apparatus of the aforementioned type which is compact, lightweight, may be hermetically sealed and can switch high voltage DC power at high altitude.
High voltage DC power is one of the most efficient, reliable and lightweight methods to generate and distribute energy. Development of high torque samarium cobalt brushless DC motors has resulted in low weight alternatives to hydraulic actuators used in weight and reliability-sensitive applications, e.g. aircraft. However, difficulties in switching high voltage DC power, particularly at high altitude, and the weight and volume of conventional DC switching apparatus capable of quenching high voltage circuits at altitudes, preclude the use of such switching apparatus in aircraft. As a result, the inability to satisfactorily switch high voltage DC power at altitude has delayed use of this power in aircraft.